For monitoring a control element, it was previously standard to measure the current flow through a precision resistor arranged at the input of the control path of the control element and, when an upper limit of a predetermined current value was exceeded, the control element was driven such that it was shut off.
The present invention is, in part, based on an object of specifying a circuit arrangement, as well as a method, for overload protection for a control element.
This and other objects are achieved by a circuit arrangement for overload protection of a first control element including a voltage source and a load. In addition, the first control element includes a first control path that selectively connects the voltage source to the load. The first control element also has at least one control input for selectively controlling the first control path and at least one output terminal connected to the load and at least one input terminal connected to the voltage source. The at least one output terminal connected to the load comprises a first control path output and the at least one input terminal connected to the voltage source comprises a first control path input. In addition, the circuit arrangement includes a protective circuit arranged in parallel to the first control path of the first control element. The protective circuit is configured to monitor voltage across the first control path and drive the control input of the first control element when a short in the load occurs such that the load is separated from the voltage source.
According to another aspect of the present invention, a method for overload protection of a first control element having a control path that connects a load to a voltage source includes first monitoring a voltage across the control path of the first control element. A control input of the first control element is then driven when a short circuit in the load occurs wherein the control path of a first control element is interrupted and the load is separated from the voltage source.
The present invention is advantageous in that due to an evaluation of the voltage potential of the control path of the control element, the control element is dependably and reliably protected against overload.
The invention yields the further advantage that an input resistor of a control element can be dimensioned smaller and, as a result, a higher voltage potential can be taken at the output of the control element.
Additional advantages and novel features of the invention will be set forth, in part, in the description that follows and, in part, will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The advantages of the present invention may be realized and attained by means of instrumentalities and combinations particularly pointed out in the appended claims.